The invention relates to a method and to a system for aiding landing of an aircraft on a landing runway, as well as to an aircraft comprising such a system.
During an approach phase before a landing, an aircraft is generally obliged to follow an approach axis of a landing runway, up to a landing position of the aircraft on the landing runway, for which the wheels of the aircraft touch the landing runway (so-called “touchdown” position). This approach axis can for example correspond to an axis of an instrument-based approach of ILS (“Instrument Landing System”) type. Immediately after landing, the aircraft performs a rollout on the landing runway according to a substantially rectilinear trajectory close to a central longitudinal axis of the landing runway.
FIG. 1 illustrates, viewed from above, an exemplary approach to a landing runway 5 by an aircraft 1. FIG. 2 corresponds to a more detailed view around the landing position of the aircraft on the landing runway. This approach is also illustrated, in a side view, by FIG. 3. In manual piloting mode, during the approach phase, the pilot must pilot the aircraft 1 along the closest possible trajectory 12 to the approach axis 10 in such a way that, on the one hand, the landing position Td of the aircraft on the landing runway is as close as possible to the central longitudinal axis 4 of the landing runway (so as to avoid putting the aircraft down alongside the landing runway) and that, on the other hand, the speed vector Vtd of the aircraft at this landing position is substantially parallel to the central longitudinal axis of the landing runway (so as to avoid exiting the runway, laterally, during rollout after landing). If a risk of exiting the runway laterally exists, the pilot must perform a go-around and carry out a new approach. During the approach to the landing runway, in particular during the final phase of the approach, the pilot must therefore monitor the trajectory of the aircraft so as to be able to detect such a risk. Document FR2948468 A1 describes a method and a device for aiding the lateral control of an aircraft during the approach phase, making it possible to signal a caution in the cockpit of the aircraft in case a risk of lateral exit from the landing runway is predicted. It would however be beneficial to have alternatives to this method and to this device.